JPS63252111A - Rice cooker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a rice cooker used in general households.
In particular, it relates to a rice cooker with improved cooking performance using an electric heater.

Conventional technology Traditionally, it has been used as an electric heater for rice cookers.

Two types of heaters are mainly used: (1) Aluminum cast heater, which is a sheathed heater embedded in aluminum casting; and (2) Sheathed heater (still-temperature type). When using a sheathed heater, an indirect heating method is used where the pot and electric heater do not come into contact with each other.Depending on the type of electric heater used, The reality is that the location of the heater has been changed.

Problems to be Solved by the Invention However, in the direct heating method described in 0) using a cast aluminum heater, the pot and electric heater are in contact with each other, so although the heat efficiency is excellent, the heat from the electric heater to the pot is Because heat transfer occurs through heat conduction, heat transfer may be unbalanced depending on the degree of contact between the pot and the electric heater, or depending on the temperature sensor installed in the center of the electric heater or the top of the pot, resulting in poor rice cooking. There was a problem that uneven cooking was likely to occur, and the overall taste was poor.

In addition, strict dimensional accuracy is required to ensure that the electric heater and pot are in close contact with each other, which increases costs, and if heat transfer becomes unbalanced due to deformation or corrosion during use, uneven cooking may occur. The problem was that it was getting worse.

On the other hand, in the indirect heating method using a high-temperature type sheathed heater (2), heat transfer from the electric heater to the pot occurs through thermal radiation, which causes stickiness in the area near the electric heater. The more distant part (upper part of the pot)
There was a problem that the cooking process was uneven and the taste of each dish was poor.

Furthermore, in order to improve this, if the sheathed heater is made into a spiral shape, it will require modification to make the heater flat, and fixing fittings, etc. will be required, which will increase the cost.

Furthermore, since the heat generating area of the heater is small, the temperature of the heater itself becomes high, and as a result, the heat shielding structure of the main body also has a drawback.

The present invention solves all of these problems.

It is an object of the present invention to provide a rice cooker '/J- which is inexpensive and capable of ideal heating without uneven cooking without requiring strict dimensional accuracy.

Means for Solving the Problems In order to solve the above problems, the present invention includes a top plate made of crystallized glass, a spirally wound heating wire, and a heating wire arranged in a tornado shape. A heat insulating base made of a heat insulating material having grooves and mainly composed of silica-alumina fiber a and alumina sol as the main binder, and a storage case made of a metal plate for storing this heat insulating base. A heating space comprising an electric heater, a pot whose outer peripheral surface is black-treated and which houses food to be cooked, and a protective frame which houses the pot, and which is formed in the protective frame around the pot. The electric heater is provided within the heating space at a predetermined distance from the pot.

Function The rice cooker of the present invention is structurally similar to the conventional indirect heating method using a sheathed heater, but the conventional rice cooker uses line heating, whereas the present invention uses surface heating. , which can heat the pot more evenly, and this structure is closer to that of an old-fashioned oven.As a result, the heat from the electric heater is in ideal conditions, which improves the taste of the rice. It is not as good as gourd, but it also significantly improves uneven cooking, which has been a problem in the past, and therefore provides a significant effect on rice cooking performance.

Additionally, since there is no contact area between the electric heater and the pot, strict dimensional accuracy is not required.

It will be cheap.

On the other hand, regarding thermal efficiency, since crystallized glass is used as the top plate, the heat from the electric heater is efficiently transmitted to the pot through both heat transmission and heat radiation. . Furthermore, since the outer peripheral surface of the pot is black-treated, it can efficiently absorb heat from the electric heater.

Furthermore, since the heat insulating base of the electric heater uses a heat insulating material mainly composed of silica-alumina fibers, the heat of the electric heater does not move to the bottom surface, but moves to the top surface where the pot is located.

For this reason, the thermal efficiency does not drop significantly compared to the conventional indirect heating method using a sheathed heater.

From the above explanation, the rice cooker of the present invention does not require strict dimensional accuracy, is inexpensive, and can perform ideal heating without uneven cooking.

Furthermore, in the present invention, since a heat insulating material containing silica-alumina fiber as the main component and alumina sol as the main binder is used as the heat insulating base of the electric heater, excellent electrical properties can be obtained. Even in a humid atmosphere, no significant deterioration of electrical properties is observed, so a rice cooker with safe electrical properties can be obtained.

EXAMPLE A specific example of the present invention will be described below with reference to FIGS. 1 to 6. In the figure, reference numeral 1 denotes a rice cooker main body having a substantially bottomed cylindrical shape with an open top surface, and a substantially cylindrical protective frame 3 that closes the pot storage section is disposed inside this main body 1 via a heat insulating material 2. The outer periphery of the upper end of the protective frame 3 is fitted into an annular upper frame 4 made of heat-resistant plastic that is fitted around the inner periphery of the upper end of the main body 1. Reference numeral 6 denotes a pot having an outwardly protruding flange 6 formed at the upper opening edge, and this pot 6 is disposed within the protective frame 3 by placing the flange 8 on the upper surface of the upper frame 4. Further, the outer peripheral surface of the pot 6 is subjected to a black treatment 6a using black alumite using an inorganic heat-resistant dye.

7 is an electric heater, which is made of the following members.

It is configured. That is, 71L is a top plate made of colored crystallized glass, and a hole 7' is provided in the center. 7b is a top plate holder used to fix the top plate 7a, and this top plate holder 7b is made of 5118430, and a female thread 7b' is provided on the inside of the outer peripheral surface. 7C is a heat insulating base made of a heat insulating material whose main components are silica and alumina fibers, and alumina sol as the main binder.

This heat insulating base 7C is provided with a spiral groove 7d and a hole 7C1 in the center. 7e is a spirally wound heating wire, and this heating wire 7e is disposed in a groove 7d provided in the heat insulating base 7C. 7f is 5U84
Consisting of 30 and electric heating? a71! This storage case 7 stores the heat insulation board 7C installed.
A hole 7f' is provided in the center of f, and
Convex lips 7g, 7g' on the inner and outer peripheral surfaces
is provided, and furthermore, a male thread 7h is provided on the outside of the outer peripheral surface. Reference numeral 71 denotes a hole 7&' in the center where the top plate 7a, the heat insulating base 7C and the storage case 7f are respectively provided.
, To', and 7f'.

The electric heater 7 fixed by the above members is supported by a support member (not shown) provided at the inner bottom of the protection frame 3. Moreover, a heating space 8 exists between this electric heater 7 and w45.

Reference numeral 9 denotes a heat-sensitive element for detecting the end temperature of rice cooking, which is attached to the protective frame 3. Reference numeral 10 denotes a lever interlocking with the heat-sensitive element 9, and reference numeral 11 denotes a microswitch for controlling energization of the electric heater 7. This microswitch 11 is turned on and off by the lever 10. 12 is a display plate attached to the main body 1. Reference numeral 13 denotes an operation button, which is inserted into the front hC lever 10. Reference numeral 14 denotes a lid, and this lid 14 is attached to the upper opening of the main body 1 so as to be openable and closable.

The operation of the rice cooker of the present invention having such a configuration will be explained first. First, washed rice 21 and water 22 are placed in the pot 6, and then the pot 6 is placed in the protective frame 3 and the lid 14 is closed. Then, when you press the operation button 13,
When the lever 1o rotates, the heat-sensitive element 9 that is linked to the lever 1o operates, and the rice is cooked, and the microswitch 11 is turned on and the electric heater 7 is energized.

When the electric heater 7 generates heat, the air in the sealed heating space 8 is heated, and the pot 6 is heated via this heated air. By heating this pot 6,
Rice 21 is cooked.

When the water 22 in the pot 6 is completely absorbed by the rice 21, the bottom of the pot 6 becomes empty and the temperature rises rapidly. At this time, the temperature of the heat-sensitive element 9 also rises, and the lever 1
0 to open the microswitch 11. As a result, the power supply to the electric heater 7 is cut off, and rice cooking is completed.

On the other hand, in order to evaluate uneven cooking during rice cooking using the rice cooker of the present invention, a temperature rise curve of each part of the pot 5 shown in FIG. 4 was measured.

In Fig. 4, the outer diameter d of the pot 6 is φ220, the mu point is the center point of the upper part of the rice 21, the D point is at the same height and 8011N away from the center point, and the 0 point is the bottom of the pot 6. More than 1011
The upper center point, 2 points, is the same height as the 0 point, the center point, 9a
Point 8 indicates the middle part between point M and point 0, and point E indicates the middle part between point D and point 2.

FIG. 5 shows the temperature rise curve during rice cooking at 1.81 (water level #i!h is approximately 90 m) at these six measurement points.

For reference, the temperature rise curve for the indirect heating method using a conventional sheathed heater is also shown in the sixth table.
Shown in the figure.

In addition, in this Figure 6, there are 1 people', B', C', and D'.

Each part of E' and F' is the person in Figure 4, B, C,
D.

Corresponds to each part of E and F.

As is clear from a comparison of FIG. 5 and FIG. 6, in the rice cooker of the present invention, there is very little temperature variation when the temperature is raised and around 100°C. For this reason, when rice is cooked using the rice cooker of the present invention, the uneven cooking that has been seen in the past hardly occurs, and as a result, ideal heating with less uneven cooking can be achieved.

Effects of the Invention As is clear from the above description, according to the present invention, a top plate made of crystallized glass, a spirally wound heating wire,
It has a groove in which the heating wire is arranged in a spiral shape, and
The electric heater consists of a heat insulating base made of a heat insulating material whose main component is alumina fiber and alumina sol as the main binder, and a storage case made of a metal plate that houses the heat insulating base. and a pot for storing food to be cooked, and a protective frame for storing the pot, the protective frame is provided with a heating space formed around the pot, and the heating space is provided with a heating space formed around the pot. Since the electric heater is provided at a predetermined distance from the pot, it is possible to provide a rice cooker that is inexpensive and capable of ideal heating without uneven cooking without requiring strict dimensional accuracy.

[Brief explanation of drawings]

FIG. 1 is a cutaway side view of a rice cooker showing an embodiment of the present invention;
Figure 2 is an enlarged sectional view of the λ section in Figure 1, Figure 3 is a sectional view of the electric heater in the same rice cooker, Figure 4 is a configuration diagram showing each part of the rice cooker when measuring the temperature of the pot, FIG. 5 is a graph showing the temperature rise curve of each part of the pot in the same rice cooker, and FIG. 6 is a graph showing the temperature rise curve of each part of the pot in the rice cooker using the conventional sheathed heater. 3...protection frame, 6...fi, 5a...
...Black processing. 7... Electric heater, 7 &... Top plate, 7
C...Insulation base, 7d...Groove, 78...
...Heating wire, 71-...Storage case, 8...
...Heating space section. Name of agent: Patent attorney Toshio Nakao and 1 other person3-
Protective frame m2 Figure 7 q Also storage goose Figure 4 Figure 5 (Separate figure 6

Claims (1)

[Claims] It has a top plate made of crystallized glass, a spirally wound heating wire, and a groove in which the heating wire is arranged in a spiral shape, and has silica-alumina fiber as the main component and alumina sol as the main binding material. An electric heater consists of a heat insulating base made of a heat insulating material, a storage case made of a metal plate that houses the heat insulating base, a pot whose outer peripheral surface is black-treated and stores food to be cooked; a protective frame for storing a pot, the protective frame is provided with a heating space formed around the pot, and the electric heater is provided within the heating space at a predetermined distance from the pot. rice cooker.